Ion channels of the nuclear membrane of hippocampal neurons.

Rise in Ca(2+) concentration in the nucleus affects gene transcription and has been implicated in neuroprotection, transcription-dependent neuronal plasticity, and pain modulation, but the mechanism of regulation of nuclear Ca(2+) remains poorly understood. The nuclear envelope is a part of the endoplasmic reticulum and may be one of the sources of nuclear Ca(2+) . Here, we studied ion channels in the nuclear membrane of hippocampal neurons using the patch-clamp technique.

Nuclear Ca2+ signalling in cerebellar Purkinje neurons.

An increase in nuclear Ca(2+) concentration may activate nuclear Ca(2+)-sensitive proteins and thereby regulate gene transcription. Ca(2+) can enter the nucleus from the cytoplasm either through nuclear pores or less certainly by release from the nuclear envelope. Recent studies indicate that the nuclear membrane of cerebellar Purkinje, but not granule neurons, contains multiple inositol 1,4,5-trisphosphate receptors (InsP(3)Rs) localized to the inner nuclear membrane.

Spontaneously active and InsP3-activated ion channels in cell nuclei from rat cerebellar Purkinje and granule neurones.

Increases in Ca(2+) concentration in the nucleus of neurones modulate gene transcription and may be involved in activity-dependent long-term plasticity, apoptosis, and neurotoxicity. Little is currently known about the regulation of Ca(2+) in the nuclei of neurones. Investigation of neuronal nuclei is hampered by the cellular heterogeneity of the brain where neurones comprise no more than 10% of the cells.